ASTM: D3557A: Cadmium, Method A: Atomic Absorption, Direct
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Official Method Name
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Standard Test Methods for Cadmium in Water |
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Current Revision
| 1995 |
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Media
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WATER |
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Instrumentation
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Graphite Furnace-Atomic Absorption Spectrometer |
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Method Subcategory
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Inorganic |
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Method Source
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Citation
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Brief Method Summary
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Cadmium is determined by atomic absorption spectrophotometry. Dissolved cadmium is determined by aspirating a portion of the filtered sample directly with no pretreatment. Total recoverable cadmium is determined by aspirating the sample following hydrochloric-nitric acid digestion and filtration. |
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Scope and Application
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This test method covers the determination of dissolved and total recoverable cadmium in most waters and wastewaters. It is applicable in the range from 0.05 to 2.0 mg/L of cadmium. The range may be extended to concentrations greater than 2.0 mg/L by dilution of the sample This test method has been used successfully with reagent grade water, river water, wastewater, ground water, tap water, lake water, and refinery effluent. |
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Applicable Concentration Range
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0.05 - 2.0 mg/L (AA, Direct); 5 - 200 ug/L (AA, Chelation-Extraction); 1 - 100 ug/L (Differential Pulse Anondic Stripping Voltammetry); 2 - 10 ug/L (AA, Graphite Furnace) |
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Interferences
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Calcium concentrations above 1000 mg/L suppress the cadmium absorption. At 2000 mg/L of calcium the suppression is 19 %. Sodium, potassium, sulfate, and chloride (9000 mg/L each), magnesium (4500 mg/L), iron (4000 mg/L), nitrate (100 mg/L), and nickel, lead, copper, zinc, cobalt, and chromium (10 mg/L each), do not interfere. Background correction or a chelation-extraction procedure (see Test Method B) may be necessary to determine low levels of cadmium in some waters. |
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Quality Control Requirements
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See ASTM Practice D3919 |
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Sample Handling
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Collect the samples in accordance with the applicable ASTM standard as follows: Practices D 3370, Practice D 1066, and Specification D 1192. Samples shall be preserved with HNO3 (sp gr 1.42) to a pH of 2 or less immediately at the time of collection, normally about 2 mL/L of HNO3. If only dissolved cadmium is to be determined, the sample shall be filtered through a 0.45-mm (No. 325) membrane filter before acidification. |
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Maximum Holding Time
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The holding time for samples may be calculated in accordance with Practice D 4841. |
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Relative Cost
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$201 to $400 |
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Sample Preparation Methods
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